Wood impregnation.



H: (3. JENNISUN.

WOOD lMPREGNATlOM.

APPLiC/f-TIQN 'FiLED MAYZO, i915 I Patented Aug. 21, 1917.

PICKS f'lEil PIE. 5

BEST AVAILABLE COP GFFICE.

HARRY G. JENNISON, or TOLEDO, 01110.

\VOOD IMPREGNA'IION.

Specification of Letters Patent. Patented A 21, 191

Application filed May 20, 1915. Serial No. 291.259

orous material cs )eciall as to C(HltllW'llllG cell. walls thereof.

This invention has utility when incorporated for-asepticizing wood, especially piles and paving blocks.

Referring to the drawings:

Figure l is an enlarged section of porous material; transversely ot' the extent of the cells therein;

Fig. 21s an enlarged section oi. porous material, longitiulinally ot the extent of the I cell's therein;

Fig. 3 is a \"ic\\"similar to Fig l, with a portion of 't1he cells fully charged or filled with impregnating substance;

Fig. 4 is a view similar to Fig. 2 showing full charging superficially, or coating extending along the eells; v

Fig. 5 is aview similar .to Fig. 1 slurwing the cell Wall painting or coating-cfi ected by dispersing a superficial full charge throughout the material; I

Fig. 6 is a view similar to Fig. 2 showing uniform distribution by air pressure action of the fractionhl full charge of impregnating substance. of water )rooting solution throughoutthe material; and y Fig. 7 is a piece of timber or paving block of the asepticized material.

Considering as an instance of porous material the wood block 1. itcomprises the rapid growth or. open cells land the slower growth or smaller cells '3, usually alter natin as the former for spring and the. latteri or summer or drier season growing) Noting this variation in a single. block of Wood, and having also to contend with the variations in cell size in ditl'erent pieces of timber, it may be desirable in some instances to take steps to bring the batch of material for a single treatment to a measure of uniformity. To this end the material may be placed in a vessel and subjected to steam pressure of say from ten to thirty pounds, depending upon the moisture content and thickness of the timber. The moisture content is thus equalized. and by tl ien-shutting off the steam and pulling a 'acunm of twenty 'to twenty-six inches of mercury colinnn, the armed timber tends to give up its excess moisture.

'ith the charge of material still in the vessel and the vacuum released, it may now be submerged in an imprcgimtiug solution 0' asepticizing liquor, say for waterproofing purposes, a lrvdrocarbon or hot heavy tar product. llydraulicpressure may be applied by forcing substance into the vessel while keeping the material submerged in the lllllfl'tglltttltlff substance 4 to fully charge or till the cells adjacent the exposed faces of the material (Figs: 3, 4 In this treatment the material is densely coated or superficially fully charged with the tar 4.

The hydraulicpressure may be released and the surplus pr servative liquor drawn oil' to leave the material now coated but unsubmergcd as n; the impregnating substance.

The coating or impregnating may-begaged as desired as to duration and amount of substance charged. For coal tar or oil' in long leat yellow pine timber in three inch lengths longitudinally of the cells, a 125 pound pressure for two hours has been found to sut'tlce. \Vood so treated as to coating or impregnating, may now be sub jected to a fluid or air pressuresutticient to ditl'use the oil throughout the timber for, Say one and one haltzhours. This gaseous or pneumatic pressure in excess of the impreg-- nai ing pressure has a dispersing action upon the. impregnating substance, distributing it tln-oughont-the material to paint and fully 'coat the cell walls 5, 6 (Figs. 5, 6), While leaving the cells open.

'llpon release of this gas pressure inthe vessel, the expanding ai'r in escaping from the wood exudes therefrom any cell filling excess of 'impregnating substance, leaving the timber 7 fully charged as coating its cell walls only. With these cell walls fully n'at'erprooted or asepticiiced, they are fortified to resist weathering attacks. Moisture entering the cells and discharging therefrom need not atl'ect.the wood. if the walls do not drink up such moisture. With the wallsnot drinking up the moisture, the wood is not expanding with moisture and shrinking upon drying out. Jhrrtln-zrmore, there is not the ObjPCtlUIltlblB oozing out of impregnating substance from fully charged superficial cells, but the wood is fully treated at a minimum of expense in the volume of impregnating substance.

In the production of wood'pavements from blocks as treated herein, there is absence of any objectionable oozings or other deterrent conditions, even in the early use, and this Without detracting from the permanence of the pavement in resisting decay, andwith a structure which stays in ,shape as initially laid.

In the subjecting to air pressure for diffusion of oil throughout the timber or paving blocks, this pressure may be sovrun up as to seemingly slip past the oil in the cells of the Wood, so that upon the completion of this step and removal of the air pressure the excess liquid for painting the cells is expressed from the timber.

W'hat is claimed and it is desired to secure by Letters Patent is;

1. The method of distributing a superficially dense coating throughout the mass of a porous substance embodying the filling of the outer pores with the impregnation material in excess of the coatingrequirements "of the pores of the substance, dissipating such material throughout the pores of the unsubme'rged substance and eliminating the surplusof such material by the application of a gaseous pressure, and the release of such pressure to exude the surplus of such material from the substance.

2. The method of coating the cell Walls of ood embodying uniformly moistening the wood bysteaming, superficially fully charging the Wood with impregnating substance by hydraulic pressure in excess of a quantity for coating the cell walls of the wood, dissipating such impregnating substance throughout the unsubmerged Wood by subjecting to a gaseous pressure and then rc1n0\' ing the excess of the impregnating substance from the Wood by increasing such gaseous pressure, and releasing the pressure to effect exuding of surplus of the substance from the wood.

3. The method of expressing cell filling impregnating substance from porous material includin subnierging the material at at mospheric pressure, applying hydraulic pressurevto impregnate the subi nerged material, releasing such pressure, drawing off the excess impregnating substance to leave the ma terial unsubmergcd, dissipating the impreg nating substance throughout the material by gaseous pressure, and removing the surplusage of impregnating substance-from the material by forcing the gas to a penetration in the material, and releasing the pressure to cause the escaping gas to exude the impregnating substance from the material.

In testimony whereof I hereunto aflix my signature.

HARRY G. JENN'ISON. 

